raster2polygon() now uses a dynamic zoom factor to avoid crashes ot timeouts...

raster2polygon() now uses a dynamic zoom factor to avoid crashes ot timeouts in case of very large raster arrays.

Signed-off-by: Daniel Scheffler <danschef@gfz-potsdam.de>

py_tools_ds/geo/raster/conversion.py

@@ -54,9 +54,9 @@ def raster2polygon(array, gt, prj, DN2extract=1, exact=True, maxfeatCount=None,
 
     # downsample input array in case is has more than 1e8 pixels to prevent crash
     if not exact and array.size > 1e8:  # 10000 x 10000 px
-        zoom_factor = 0.5
+        zoom_factor = 1e8 / array.size
 
-        # downsample to half size, nearest neighbour
+        # downsample with nearest neighbour
         from skimage.transform import rescale  # import here to avoid static TLS import error
         array = rescale(array, zoom_factor, order=0, preserve_range=True, mode='edge').astype(bool)